Applications of biomass Stirling engines for electrification -A case study of rural areas in Bolivia.

Abstract: This report provides a study and a simulation of a feasible system configuration for the implementation of a Stirling engine for electrification of rural areas in Bolivia. The aim of the review is to determine if a hybrid system combining a biomass-fired Stirling engine and photovoltaic technology may respond to a basic electricity need. An introductory literature study about the Stirling engine technology and the energy resources and characteristics of Bolivia leads to a further proposal of the selected system for rural electrification. The chosen Stirling engine for this study is a 3 kW electric output engine combined with a PV array of 0.9 kW and a battery bank with a capacity of 1200 Ah. The power demand that must be satisfied is based on a rural village in the department of Beni with an amount of 24 households. The simulation is performed in the software Homer Energy where an energy balance between the generated power and the demand can be analysed in order to optimise the power generation strategy. Two scenarios are simulated with monthly demands of 45 and 60 kWh per household. Results from the study indicate that the decision on the size of the Stirling engine must be attached to the demand that is going to satisfy in order to avoid insufficient or excessive power production. In addition, although the PV technology allows an increase on the power demand that the system can handle and makes it more flexible, its contribution is not of the same order of the Stirling engine. The described system configuration is able to attend a demand up to 55 kWh/day and a peak power of 3.8 kW. In conclusion, Stirling engines have the potential to become a good solution for rural electrification, especially when making use of CHP strategies to increase the overall efficiency of the energy generation and fulfil both the electric and thermal demands of rural populations.